Due to the frequency of injury to various ligaments such as the anterior cruciate ligament (ACL), especially in sports, and similar injury to other ligaments and related structures, there is a great deal of prior art dealing with a replacement of these structures with ligament grafts. Much of this prior art is concerned with ensuring proper placement of bone tunnels drilled in the bones intended to receive the opposed ends of the graft ligament, such as the tibia and femur, with proper preparation of the surgical site, i.e., by removing sufficient bone to allow the graft to function properly, and with preparation of suitable graft ligaments, commonly by harvesting donor soft tissue or bone/tendon/bone structures from the patient. See generally, “The Paramax ACL Guide System Surgical Technique”, a brochure published by Linvatec Corporation of Largo, Fla. in 1992, and incorporated by reference herein, which provides useful background on one type of overall ACL replacement procedure. Other sources of replacement ligaments, including allograft and autograft ligament substitutes, are within the skill of the art and are intended to be included within the term “graft ligament” as used herein.
The present invention does not address these aspects of ACL reconstruction, but instead addresses the problem of securely anchoring the graft ligament in the bone tunnels. More specifically, the present invention relates to improvements in devices to be disposed at the outer ends of bone tunnels to provide a fixing point for securing an end of a graft ligament in place.
The prior art shows anchors for ligaments wherein the ligament is sutured to an anchor configured to abut the outer opening of the bone tunnel, and remain outside the bone tunnel. See for example Graf et al. U.S. Pat. No. 5,306,301 disclosing various elongated bodies intended to be passed through the bone tunnels and rotated after exiting the tunnels, so as to be retained against the outer surface of the bone. See also U.S. Pat. No. 5,139,520 to Rosenberg. This category of devices includes generally elongated relatively thin plates designed to be aligned with a bone tunnel while passing through the bone tunnel and then designed to be manipulated into a transverse position across the bone tunnel to prevent a graft attached to the device from being detached from the bone tunnel. These devices include a plurality of apertures designed to receive graft retaining sutures as well as manipulating sutures intended to manipulate the device into a transverse orientation. The manipulation of such devices is sometimes challenging and there exists a need in the art for improvements in graft fixation devices and procedures. Furthermore, such devices are not easily repositioned or removed once set in place. Accordingly, there exists a need for devices which can be easily repositioned.
It is an object of this invention to provide a graft ligament anchor capable of minimizing the degree of manipulation required to set the anchor transversely to the bone tunnel. It is also an object of this invention to provide a graft ligament anchor capable of being easily repositioned or removed.